A flat-plate-shaped device under test such as a semiconductor integrated circuit undergoes an electrical test to determine whether or not it is manufactured in accordance with its specification. The electrical test of this kind is performed by using an electrical connecting apparatus, such as a probe card, a probe block, a probe unit, or the like, in which a plurality of probes or contactors to be thrust to respective electrodes of the device under test are arranged on a board such as a wiring board, a probe board, or the like. The electrical connecting apparatus of this kind is used to electrically connect the electrodes of the device under test to electrical circuits of a tester.
In one electrical connecting apparatus of this kind, there are a plurality of probes or contactors that are supported on the lower surface of a probe board in a cantilevered manner, and in which the probe board is arranged under a wiring board via an electrical connector to perform a power-supply electrical test of un-diced multiple integrated circuits formed on a semiconductor wafer at a time or in several batches as generally described in International Patent Publication No. WO 2007/108110.
However, in recent years, since there is an increasing demand for smaller and more high-density integrated circuits, wherein each recent integrated circuit, the pitch of pad electrodes has been reduced significantly, and the pad electrodes themselves have a tendency toward fine pitch. Also, for the purpose of increasing test efficiency, there is a demand for performing an electrical test of more integrated circuits at a time as in the case of the above electrical connecting apparatus.
In the electrical connecting apparatus for performing an electrical test of more integrated circuits in which the pad electrode pitch is reduced as in the above case, more contactors must be used, and thus the number of internal wires (especially wires as signal transmission paths) in the probe board and the wiring board electrically connecting a tester to the pad electrodes of the integrated circuits via the contactors is increased. Consequently, these internal wires are inevitably complicated and massed.
In the electrical connecting apparatus whose internal wires are complicated and massed as above, when defective integrated circuits having insulation failures, electrical short-circuit, etc., electrical signals in the internal wires for these defective integrated circuits have an adverse effect on signals to be input to the other good integrated circuits that may be tested simultaneously. As examples of such adverse effects, voltage reduction, waveform break, etc. of the signals to be input in the good integrated circuits may occur, in which case, a normal test is not performed.
To cope with the above situation, one solution adopts a technique of providing the wiring board or the probe board with a resistor electrically connected to each internal wire to electrically connect the tester to the integrated circuit via each internal wire and resistor as generally described in Japanese Patent Application No. 2007-128292, which is incorporated herein by reference.
However, with such a technique, it is difficult to form the resistor having a desired resistance value in the board. Also, the resistance value of each resistor and the internal wire can be measured only after the board to which the resistor is disposed is completed. Thus, in such a technique, it is impossible to determine whether or not the completed board is good at an early stage. The determination of whether or not the completed board is good is done by determining whether or not the resistance value of each resistor and each internal wire has a desired value.
For a defective board, work to repair the internal wire etc by scraping off a multi-layered wiring board comprised in the probe board or making a hole in the board is done. However, in this repair work, troublesome and precise work must be done since the internal wire is fine. As a result, such repair work can be done only by skilled workers. Providing the board with the resistors requires enormous amount of time and energy in the resistors providing work itself and prevents yield improvement of the board.